The War, 31 May 1814 (vol. 2, no. 50, whole no. 102) - Newspaper

Volumes of interest were published between 1812 and 1815 with articles about the War of 1812.

Investigation of the role of the nucleus accumbens in amphetamine-induced 50 kHz ultrasonic vocalizations in the rat

There is extensive evidence that the mesolimbic dopamine system underlies the production of 50 kHz ultrasonic vocalizations in rats. In particular, the shell of the nucleus accumbens is associated with generation of frequency modulated 50 kHz calls (a specific type of 50 kHz call which can be subdivided into various subtypes). There is also evidence that amphetamine administered systemically preferentially increases the proportion of trill and step calls compared to other frequency modulated 50 kHz subtypes. The purpose of this study was to investigate the effect of drug administration route and the role of the nucleus accumbens shell in amphetamine-induced 50 kHz call profile in the rat. Three experiments investigated this by using subcutaneous and intra-accumbens microinjections of amphetamine, as well as procaine (a local anesthetic) blockade of the nucleus accumbens. Ultrasonic vocalizations were recorded digitally from 24 rats and were analysed for sonographic structure based on general call parameters. The results of the three experiments were partially supportive of the hypotheses. Systemic amphetamine was found to induce greater bandwidth in 50 kHz calling compared to spontaneous calls in a vehicle condition. Systemic amphetamine was also found to preferentially increase the proportion of trill and step subtypes compared to vehicle. Moreover, there was no difference in the proportions of 50 kHz subtypes resulting from intracerebral or systemic application of amphetamine. There was, however, a significant difference for bandwidth, with systemic amphetamine inducing greater bandwidth over intraaccumbens application. Procaine blockade of the nucleus accumbens shell paired with subcutaneous amphetamine produced no difference in bandwidth of calls compared with those after a vehicle pre-treatment similarly paired. There was no reduction in the proportions of trill and step 50 kHz subtypes as well, with the procaine condition showing significantly greater proportion of step calls. The results of the study support a role for the iii nucleus accumbens shell in the amphetamine-induced changes on 50 kHz call profile. They also indicate there are more regions and pathways involved in generating 50 kHz calls than the projections from the ventral tegmental area to the nucleus accumbens. The implications of this work are that frequency modulated 50 kHz subtypes may be generated by distinct neurophysiological mechanisms and may represent a profitable avenue for investigating different circuits of 50 kHz call categories in the rat.

HG 226.50-226.60 Thin Section

Dark brown sediment with manly small sized clasts. Some medium and large clasts also present. Clasts range from sub-angular to sub-rounded. Lineations can be seen throughout the sample. Minor patches of clay/organic rich domains can also be seen as well as minor grain stacking.

HG 244.40-244.50-A Thin Section

Dark brown sediment with sub-angular to sub-rounded clasts. Rotation structures and lineations are common. Clasts ranging from small to large in size. Many large grains are fractured. Minor amounts of grain stacking and crushing can be seen. A few clay and organic rich domains can be seen.

HG 421.50-421.60

Light brown sediment with clasts that range from small to large in size. The clast shape ranges from sub-angular to sub-rounded. Lineations and rotation structures are abundant in this sample. Edge-to-edge grain crushing is present as well. There are areas of light and dark sediment throughout the sample. A few comet structures can also be seen.

HG 437.50-437.55

Light brown sample with clasts ranging from small to large. The clast shape ranges from sub-angular to sub-rounded. Grain crushing is common in this sample and mainly involves the larger clasts. Many grains are also crushed into one another. The larger grains are also fractured. Lineations and faint water escape structures can also be seen. This sample also contains a finer grained domain, darker in colour.

HG 18.50-18.55

This sample contains grains that range from small to large in size. The clast shape ranges from angular to rounded. Many grains are fractured and grain crushing is commonly seen. A few necking structures and rotation structures can also be seen.

HG 46.40-46.50

Brown sediment with areas of clay rich material (darker brown). Clasts range from small to large in size. Clast shape ranges from angular to rounded. Rotation structures and necking structures were abundant in this sample. Some lineations and grain stacking can also be seen throughout the sample.

59.40-59.50

Brown sediment with clasts ranging from small to medium in size. Clast shape ranges from angular to sub-rounded. Lineations are common in this sample along with grain crushing. A few comet structures can also be seen.

HG 70.40-70.50

Dark brown sediment with clasts ranging from small to large in size. Clast shape ranges from angular to sub-rounded. Lineations and comet structures can commonly be seen throughout the sample. Some rotation structures and grain crushing can also be seen in varying amounts.

HG 82.50-82.65

Dark brown sediment with well dispersed clasts ranging from small to medium in size. Clast shape ranges from sub-angular to sub-rounded. Lineations can commonly be seen throughout the sample. Comet structures can also be seen in minor amounts.

HG 114.40-114.50

Brown sediment with clasts ranging from small to medium in size. Clast shape ranges from angular to sub-rounded. Lineations are the most abundant microstructure, but this sample also includes some comet and rotation structures as well.

HG 129.50-129.60

Brown sediment with multiple domains. There are two finer grained domains that contain a few small clasts. These two can be distinguished based on the abundance of clay material(darker brown). The coarse grained sediment contains clasts ranging from small to medium in size, and angular to sub-rounded in shape. This domain contains lineations, rotation structures, comet structures, and some edge-to-edge grain crushing.

HG 168.50-168.60

Brown sediment with three main domains; two different fine grained domains and one coarse grained domain. The fine grained domains can be distinguished based on the abundance of organic material (darker). Both domains contain lineations. The coarse grained domain contains clasts ranging from small to medium in size and angular to rounded in shape. Rotation structures, lineations and comet structures can be seen in this domain. It also contains some fractured grains.